1. Field of the Invention
The present invention relates to a producing method of a wired circuit board and, more particularly, to a producing method of a wired circuit board which is preferably used for the production of a suspension board with circuit.
2. Description of the Related Art
In a hard disk drive, a suspension board with circuit is used in which a wired circuit pattern connected to a magnetic head is integrally formed in a suspension board for supporting the magnetic head. The suspension board with circuit includes the suspension board made of stainless steel, an insulating base layer formed thereon and made of polyimide, and a wired circuit pattern formed on the insulating base layer, and made of copper.
As a producing method of such a suspension board with circuit, a method has been proposed in which, in a suspension board with circuit wherein, e.g., a conductive pattern including terminal portions and lead portions is formed on an insulating layer made of polyimide and provided on a stainless steel foil base material, a covering layer is formed to cover the conductive pattern except for the terminal portions and the lead portions, electrolytic nickel plating and electrolytic gold plating are successively performed with respect to the terminal portions to form terminals, and then the lead portions are removed by chemical etching (see, e.g., Japanese Unexamined Patent Publication No. 10-265572).